The flora infestation of sewer lines has long been a serious problem. After sewer lines have been laid, they often develop leaks around the joints due to settling of the ground, earthquakes, or vibration of the earth due to traffic roadways. These areas of leakage are then often penetrated by roots, which in time can clog or rupture the sewer line. Once this has occurred, the sewer line must be removed and replaced. This replacement is not only very expensive, but also destroys the surrounding flora.
In order to prevent flora damage to sewer lines, various herbicides have been used as have various application methods. The most common method of attacking flora infestations within sewer lines is by flushing a herbicide such as copper surf ate through the line. This method is only partially effective since only the flora in the lower, fluid carrying portion of the line is treated while flora in the upper portion of the line remains untreated. Also known to the art are chemically foaming mixtures which produce foam in the presence of sewer water in order to carry the herbicide throughout the interior of the line. While this method is more effective, it is also quite expensive and requires the use of a large amount of herbicide.